FMF Gnarly jetting Q's

[[email protected]]

sweet this thread helped me out alot , THanks bhq

[nomad]

I hope I just figured out that my jetting is too lean (too much air), not that it's good (revs strongly from bottom up with the choke half out, too rich (smokey) with the choke all the way out and hardly any smoke and bogs when the choke is pushed in). Dynojet doesn't seem to provide a "pilot circuit" per the below link. I looked in the dyno jet manual which came with the kit and they don't mention a pilot, just a main. I turned the airscrew out .5 and it's better with the chokeoff, but not great. So this is what I found on-line:

 

http://www.dynojet.com/motorjet.shtml

 

Guess I'll be researching/learning about the float level and slide. This is a great forum with great people trying to help out and sharing their experience(s). When I can saddle up again (about 3 weeks) and get her to the shop to find out exactly what's wrong, I'll definately update this thread for future riders with the same trouble.

 

THANKS AGAIN!

 

P.S.- would changing the premix ratio from 32:1 to 40:1 help any (Motorex 2T) oil?

Edited August 28, 2006 by nomad

[[email protected]]

I hope I just figured out that my jetting is too lean, not that it's good (revs strongly from bottom up with the choke half out, too rich (smokey) with the choke all the way out and hardly any smoke and bogs when the choke is pushed in). Dynojet doesn't seem to provide a "pilot circuit" per the below link. I looked in the dyno jet manual which came with the kit and they don't mention a pilot, just a main. I turned the airscrew out .5 and it's better with the chokeoff, but not great. So this is what I found on-line:

 

http://www.dynojet.com/motorjet.shtml

 

Guess I'll be researching/learning about the float level and slide. This is a great forum with great people trying to help out and sharing their experience(s). When I can saddle up again (about 3 weeks) and get her to the shop to find out exactly what's wrong, I'll definately update this thread for future riders with the same trouble.

 

THANKS AGAIN!

 

 

[cbn70]

Glad some of this info is helping ya. If you want a good book to read about jetting mikuni carbs, get Carb Tuning Handbook by Olav Aaen. I got it from a snowmobile shop. Might be able to find it online. It is really the best book I have found explaining the different mikuni carb circuits and how to change them to make them work for your particular application.

[The Faster Cracker]

so whats the story man? is it jetted right now?

[nomad]

No, not yet. I just had surgery on my lower back about 2 weeks ago and I can't do anything yet. I plan on taking her back to my friend (dealership manager) late next week after returning from Atlantic City. I want to watch them tear the carbs down so I can see how it's done. He also wants me to test the jetting on their track after the changes, so he doesn't have to keep hearing me bitch! Thanks for asking, and I'll post the results/fix when it's working well.

[nomad]

Sorry I forgot to update this thread. The dealership went up one on the main and now it runs very well. The main is a 280, but I don't know the clip position.